On Tue, Aug 01, 2023 at 01:04:32PM +0200, Christoph Hellwig wrote: > On Mon, Jul 31, 2023 at 06:28:01PM +0200, Hannes Reinecke wrote: > > The flush machinery is sending flushes before and/or after the original > > request (preflush/postflush). For blocked transports (ie during FC RSCN > > handling) the transport will error out commands depending on the FAILFAST > > setting. If FAILFAST is set the SCSI layer gets an STS_TRANSPORT error > > (causing the I/O to be retried), but STS_ERROR if not set (causing I/O to > > failed). > > > > So if the FAILFAST setting is _not_ aligned between flush_rq and the > > original we'll get an error on the flush rq and a retry on the original rq, > > causing the entire command to fail. > > > > I guess we need to align them. > > But you can't, because multiple pre/postflushes are coalesced into a > single outstanding flush request. They can and will not match quite > commonly. And if you mean the REQ_FAILFAST_TRANSPORT added by dm - this will never even see the flush state machine, as that is run in dm-mpath which then inserts the fully built flush request into the lower request queue. At least for request based multipath, bio could hit it.
